The Sixth Floor Orchestra was founded by harpsichordist Anssi Mattila in 1989. In the early years it rehearsed on the sixth floor of the Sibelius Academy building on Fredrikinkatu in Helsinki: hence its name. It consists of musicians well versed in the performing conventions of early music and the instruments for which each type of music was written. In addition to all the major Finnish music festivals the orchestra has appeared in many parts of Europe.

In 2001 Ondine released a recording that won great acclaim both in Finland and abroad; "The Classical Age in Finland" contained all the 18th-century Finnish orchestral music that has been preserved, and it was awarded an honorary mention in the 2001 'Record of the Year' poll by the music editors of the Finnish Broadcasting Company (YLE), as well as the Janne Prize of the Finnish National Group of the International Federation of the Phonographic Industry (IFPI) (ODE 971-2).